2022-04-04 10:59:28

by Jiabing Wan

Subject: [PATCH v2] rtla: add a tag to avoid dereferring a NULL pointer

Fix the following null/deref_null.cocci errors:
./tools/tracing/rtla/src/osnoise_hist.c:870:31-36: ERROR: record is NULL but dereferenced.
./tools/tracing/rtla/src/osnoise_top.c:650:31-36: ERROR: record is NULL but dereferenced.
./tools/tracing/rtla/src/timerlat_hist.c:905:31-36: ERROR: record is NULL but dereferenced.
./tools/tracing/rtla/src/timerlat_top.c:700:31-36: ERROR: record is NULL but dereferenced.

"record" is NULL before calling osnoise_init_trace_tool.
Add a tag "out_free" to avoid dereferring a NULL pointer.

Fixes: 51d64c3a1819 ("rtla: Add -e/--event support")
Signed-off-by: Wan Jiabing <[email protected]>
---
Changelog:
v2:
- Add the fix for timerlat.
---
tools/tracing/rtla/src/osnoise_hist.c | 5 +++--
tools/tracing/rtla/src/osnoise_top.c | 9 +++++----
tools/tracing/rtla/src/timerlat_hist.c | 11 ++++++-----
tools/tracing/rtla/src/timerlat_top.c | 11 ++++++-----
4 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index b4380d45cacd..5d7ea479ac89 100644
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -809,7 +809,7 @@ int osnoise_hist_main(int argc, char *argv[])
retval = set_comm_sched_attr("osnoise/", &params->sched_param);
if (retval) {
err_msg("Failed to set sched parameters\n");
- goto out_hist;
+ goto out_free;
}
}

@@ -819,7 +819,7 @@ int osnoise_hist_main(int argc, char *argv[])
record = osnoise_init_trace_tool("osnoise");
if (!record) {
err_msg("Failed to enable the trace instance\n");
- goto out_hist;
+ goto out_free;
}

if (params->events) {
@@ -869,6 +869,7 @@ int osnoise_hist_main(int argc, char *argv[])
out_hist:
trace_events_destroy(&record->trace, params->events);
params->events = NULL;
+out_free:
osnoise_free_histogram(tool->data);
out_destroy:
osnoise_destroy_tool(record);
diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index 72c2fd6ce005..76479bfb2922 100644
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -572,7 +572,7 @@ int osnoise_top_main(int argc, char **argv)
retval = osnoise_top_apply_config(tool, params);
if (retval) {
err_msg("Could not apply config\n");
- goto out_top;
+ goto out_free;
}

trace = &tool->trace;
@@ -580,14 +580,14 @@ int osnoise_top_main(int argc, char **argv)
retval = enable_osnoise(trace);
if (retval) {
err_msg("Failed to enable osnoise tracer\n");
- goto out_top;
+ goto out_free;
}

if (params->set_sched) {
retval = set_comm_sched_attr("osnoise/", &params->sched_param);
if (retval) {
err_msg("Failed to set sched parameters\n");
- goto out_top;
+ goto out_free;
}
}

@@ -597,7 +597,7 @@ int osnoise_top_main(int argc, char **argv)
record = osnoise_init_trace_tool("osnoise");
if (!record) {
err_msg("Failed to enable the trace instance\n");
- goto out_top;
+ goto out_free;
}

if (params->events) {
@@ -649,6 +649,7 @@ int osnoise_top_main(int argc, char **argv)
out_top:
trace_events_destroy(&record->trace, params->events);
params->events = NULL;
+out_free:
osnoise_free_top(tool->data);
osnoise_destroy_tool(record);
osnoise_destroy_tool(tool);
diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index dc908126c610..f3ec628f5e51 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -821,7 +821,7 @@ int timerlat_hist_main(int argc, char *argv[])
retval = timerlat_hist_apply_config(tool, params);
if (retval) {
err_msg("Could not apply config\n");
- goto out_hist;
+ goto out_free;
}

trace = &tool->trace;
@@ -829,14 +829,14 @@ int timerlat_hist_main(int argc, char *argv[])
retval = enable_timerlat(trace);
if (retval) {
err_msg("Failed to enable timerlat tracer\n");
- goto out_hist;
+ goto out_free;
}

if (params->set_sched) {
retval = set_comm_sched_attr("timerlat/", &params->sched_param);
if (retval) {
err_msg("Failed to set sched parameters\n");
- goto out_hist;
+ goto out_free;
}
}

@@ -844,7 +844,7 @@ int timerlat_hist_main(int argc, char *argv[])
dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
if (dma_latency_fd < 0) {
err_msg("Could not set /dev/cpu_dma_latency.\n");
- goto out_hist;
+ goto out_free;
}
}

@@ -854,7 +854,7 @@ int timerlat_hist_main(int argc, char *argv[])
record = osnoise_init_trace_tool("timerlat");
if (!record) {
err_msg("Failed to enable the trace instance\n");
- goto out_hist;
+ goto out_free;
}

if (params->events) {
@@ -904,6 +904,7 @@ int timerlat_hist_main(int argc, char *argv[])
close(dma_latency_fd);
trace_events_destroy(&record->trace, params->events);
params->events = NULL;
+out_free:
timerlat_free_histogram(tool->data);
osnoise_destroy_tool(record);
osnoise_destroy_tool(tool);
diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 1f754c3df53f..35452a1d45e9 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -612,7 +612,7 @@ int timerlat_top_main(int argc, char *argv[])
retval = timerlat_top_apply_config(top, params);
if (retval) {
err_msg("Could not apply config\n");
- goto out_top;
+ goto out_free;
}

trace = &top->trace;
@@ -620,14 +620,14 @@ int timerlat_top_main(int argc, char *argv[])
retval = enable_timerlat(trace);
if (retval) {
err_msg("Failed to enable timerlat tracer\n");
- goto out_top;
+ goto out_free;
}

if (params->set_sched) {
retval = set_comm_sched_attr("timerlat/", &params->sched_param);
if (retval) {
err_msg("Failed to set sched parameters\n");
- goto out_top;
+ goto out_free;
}
}

@@ -635,7 +635,7 @@ int timerlat_top_main(int argc, char *argv[])
dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
if (dma_latency_fd < 0) {
err_msg("Could not set /dev/cpu_dma_latency.\n");
- goto out_top;
+ goto out_free;
}
}

@@ -645,7 +645,7 @@ int timerlat_top_main(int argc, char *argv[])
record = osnoise_init_trace_tool("timerlat");
if (!record) {
err_msg("Failed to enable the trace instance\n");
- goto out_top;
+ goto out_free;
}

if (params->events) {
@@ -699,6 +699,7 @@ int timerlat_top_main(int argc, char *argv[])
close(dma_latency_fd);
trace_events_destroy(&record->trace, params->events);
params->events = NULL;
+out_free:
timerlat_free_top(top->data);
osnoise_destroy_tool(record);
osnoise_destroy_tool(top);
--
2.35.1

2022-04-10 02:37:17

by Daniel Bristot de Oliveira

Subject: Re: [PATCH v2] rtla: add a tag to avoid dereferring a NULL pointer

Hi Wan

There is a typo in the subject, and it needs a capital letter after the ':'.

I suggest using something like:

rtla: Avoid record NULL pointer dereference

Do you mind sending a v3?

On 4/1/22 14:39, Wan Jiabing wrote:
> Fix the following null/deref_null.cocci errors:
> ./tools/tracing/rtla/src/osnoise_hist.c:870:31-36: ERROR: record is NULL but dereferenced.
> ./tools/tracing/rtla/src/osnoise_top.c:650:31-36: ERROR: record is NULL but dereferenced.
> ./tools/tracing/rtla/src/timerlat_hist.c:905:31-36: ERROR: record is NULL but dereferenced.
> ./tools/tracing/rtla/src/timerlat_top.c:700:31-36: ERROR: record is NULL but dereferenced.
>
> "record" is NULL before calling osnoise_init_trace_tool.
> Add a tag "out_free" to avoid dereferring a NULL pointer.
>
> Fixes: 51d64c3a1819 ("rtla: Add -e/--event support")
> Signed-off-by: Wan Jiabing <[email protected]>

Also adding:

Acked-by: Daniel Bristot de Oliveira <[email protected]>

Thanks,
-- Daniel